In the hybridization of motor vehicles, according to the prior art, the system consisting of a combustion engine and the transmission can be equipped with a crankshaft starter generator, with an electric machine arranged co-axially in the area of the Cardan shaft for driving under electric power or for recuperation. With such an arrangement, the rear axle differential of the vehicle is driven by the transmission via one or more Cardan shafts. The rotor of the electric machine is usually connected to the Cardan shaft or to another shaft in a rotationally fixed manner with the Cardan shaft, whereby the electric machine can be used for boosting or recuperation or for driving purely under electric power when certain clutches are disengaged in the transmission so that the transmission is idling.
The speed of the Cardan shaft is determined by the transmission ratios and the driving speed desired. As a rule the structure of the electric machine is designed so that with the smallest sized electric machine, the highest possible torque can be transmitted to the Cardan shaft. For that purpose, it may be necessary to construct the electric machine so that it runs at a substantially higher speed than the Cardan shaft.
The purpose of the present invention is to indicate a design for the drivetrain of a hybrid motor vehicle, whereby the force flow is optimized.